The present invention pertains to upgrading hydrocarbonaceous materials by their thermal reaction with ether compounds. It pertains particularly to non-catalytic upgrading hydrocarbonaceous materials by thermal reactions of hydrocarbon free radicals with methyl radical and hydrogen forming chemicals such as dimethyl ether, to produce lower boiling hydrocarbon liquid products.
The main reaction in conventional catalytic hydroconversion of hydrocarbonaceous materials, such as H-Coal.RTM. and two stage coal liquefaction processes is to indirectly or directly add a hydrogen atom to the free radicals formed by thermal cracking of coal, thereby stabilizing them. The major portion of the hydrogen atoms is obtained by abstraction of hydrogen atoms from a donor solvent, which has been hydrogenated catalytically under high hydrogen pressure. Due to mass transfer and kinetic limitations, the catalytic hydroconversion process requires high pressure and has limited efficiency.
In the processes of upgrading or conversion of hydrocarbons such as coal in a H-Coal.RTM. Process or a heavy oil, i.e., residual oil, in a H-Oil.RTM. Process, these processes have been carried out by catalytic hydrogenation in a reactor having a catalyst bed. In these processes, the use of added hydrogen has been quite common as shown in Johanson U.S. Pat. No. 3,679,573 for H-Coal.RTM. in that in the process disclosed therein, an ebullated catalyst bed was used which was composed of a particulate hydrogenation catalyst.
In the H-Coal.RTM. and the H-Oil.RTM. Processes, free radicals are formed by thermal cracking and stabilized by catalytic hydrogenation. The processes are carried out at a temperature ranging anywhere from 700.degree. to 850.degree. F. and using hydrogen at a rate of 5 to 300 SCFH/Lb coal and having a high pressure of about 1500-3000 psi.
It has now been found according to the present invention that these hydrocarbonaceous materials, i.e., coal and petroleum residual oils, may be upgraded without the use of added hydrogen and a catalyst bed. The present invention uses an ether material, which under a proper temperature and low pressure (i.e., 1000 psi and less) reacts with these hydrocarbons to yield low molecular weight hydrocarbon distillate products such as naphtha, heating oil fuel, diesel fuel and a high grade of petroleum oil.